Secondary batteries which are highly applicable to various products and exhibit superior electrical properties such as high energy density, etc. are commonly used not only in portable devices but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electrical power sources. The secondary battery is drawing attentions as a new energy source for enhancing environment friendliness and energy efficiency in that the use of fossil fuels can be reduced greatly and no byproduct is generated during energy consumption.
Secondary batteries widely used at the preset include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries and the like. An operating voltage of the unit secondary battery cell, namely a unit battery cell, is about 2.5V to 4.2V. Therefore, if a higher output voltage is required, a plurality of battery cells may be connected in series to configure a battery pack. In addition, depending on the charge/discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to configure a battery pack. Thus, the number of battery cells included in the battery pack may be variously set according to the required output voltage or the demanded charge/discharge capacity.
Meanwhile, when a plurality of battery cells are connected in series or in parallel to configure a battery pack, it is common to configure a battery module composed of at least one battery cell first, and then configure a battery pack by using at least one battery module and adding other components.
A conventional battery pack generally includes a battery module and a pack case for accommodating the battery module to package the battery module. Here, the battery module may be mounted to be fixed in the pack case in order to prevent vibrations and impacts. For the fixation, in the conventional battery pack, the battery module is fixed in the pack case by using an additional coupling structure with bolts, nuts or the like.
However, the coupling structure using bolts, nuts or the like inevitably demands an additional coupling space in the pack case, which may be highly likely to cause a limitation in space inside the pack case. Also, even though the coupling space is secured, it is difficult to ensure a space for connecting the battery module and the pack case.
For ensuring such a space, the pack case should have a great size, but the increase in the size of the pack case runs counter to a slimmer structure according to the recent slimming trend.
Thus, it is demanded to develop a battery pack which may implement a slimmer structure according to the recent slimming trend and stably fix a battery module in the pack case, and a vehicle including the battery pack.